WEDNESDAY, July 9, 2014 (HealthDay News) -- Obesity is a growing problem among Hispanic Americans, especially among young adults, a new study shows.

After analyzing data from more than 16,300 Hispanics in Chicago, Miami, New York City and San Diego, the researchers found that 18 percent of women and 12 percent of men had a body mass index (BMI) over 35.

BMI is a measurement based on height and weight. People with a BMI over 30 are considered obese. A BMI over 35 is associated with increased health risks.

Even more troubling, severe obesity (BMI over 40) was most common among young adults aged 25 to 34, affecting nearly one in 10 women and one in 20 men in this age group, according to the study in the July 9 issue of the Journal of the American Heart Association.

The obesity epidemic among Hispanic Americans is "unprecedented and getting worse," study author Robert Kaplan, a professor of epidemiology and population health at Albert Einstein College of Medicine in New York City, said in a journal news release.

"Because young adults with obesity are likely to be sicker as they age, and have higher health care costs, we should be investing heavily in obesity research and prevention," he added.

More than half of severely obese Hispanic adults had unhealthy levels of "good" HDL cholesterol and high levels of inflammation, the study found. About 40 percent had high blood pressure and more than one-quarter had diabetes.

"This is a heavy burden being carried by young people who should be in the prime of life," Kaplan said. "Young people, and especially men -- who had the highest degree of future cardiovascular disease risk factors in our study -- are the very individuals who tend to neglect the need to get regular checkups, adopt healthy lifestyle behaviors and seek the help of health care providers."